Vane operating mechanism



April 1968 D. H. WILLIAMSON 3,376,018

VANE OPERATING MECHANISM Filed Dec. 21, 1966 5 Sheets-Sheet l InventoroVQ/WZUAL IW v v W, W We),

April 1968 D. H. WILLIAMSO N 3,376,018

VANE OPERATING MECHANISM Filed Dec. 21, 1966 5 Sheets-Sheet 2 InventorflOm aw 7W Wm, M t

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April 1968 D. H. WILLIAMSON 3,376,018

VANE OPERATING MECHANISM Filed Dec. 21, 1966 5 Sheets-Sheet 5 wL-a" Attorney 3 Unitid States Patent 3,376,018 VANE OPERATING MECHANISMDouglas Herbert Williamson, Derby, England, assiguor to Rolls-RoyceLimited, Derby, England, a British company Filed Dec. 21, 1966, Ser. No.603,652 Claims priority, application Great Britain, Jan. 10, 1966,

1,123/66 10 Claims. (Cl. 253-78) ABSTRACT OF THE DISCLOSURE A vaneoperating mechanism having a rotatable ring, connected by arms to aspindle extending from each vane root, rotation of the ring eifectingpivotal movement of the vane. One end of each arm is part-spherical andis received by an aperture in the ring, the aperture being so shapedthat the arm may be introduced into theaperture, and then turned to lockit in position. Each arm has a flexible portion to accommodatedeformation during operation.

This invention concerns avane operating mechanism and, although theinvention is not so restricted, it is more particularly concerned with amechanism for operating variable stator vanes of a gas turbine engine.

The term vanes as used in this specification is to be understood asincluding blades.

According to the present invention, there is provided a vane operatingmechanism comprising at least one ring, means for rotating the or eachring about its axis and through a predetermined angular range, the oreach said ring having associated therewith and being axially spaced froma plurality of angularly spaced apart vanes which are arranged about thesaid axis and each of which has a radially extending spindle rotation ofwhich effects pivotal movement of the respective vane, and an armconnecting each spindle to its ring so that rotation of the lattereiTects pivotal movement of the vanes associated therewith, each armhaving a portion which is located in an aperture in its ring and/ or inits spindle, each said portion and aperture being so formed that theportion may be relatively orientated to introduce it into the apertureand then relatively moved within the aperture to lock it in positiontherein.

Each arm preferably has a flexible part to accommodate the bending towhich it is subjected in operation. Thus each said .fiexible part may bea centrally located and relatively thin part of its arm.

The said portion of each arm is preferably part-spherical and is locatedin a part-spherical aperture, each said portion having been originallyintroduced into at least one part of the aperture which isnon-spherical. Thus, each part-spherical aperture may have twodiametrically oppositely disposed straight sided enlarged parts, thesaid portion of each arm having parallel fiat sides for reception withinthe said enlarged parts.

Each said aperture is preferably provided in the or a ring, each armbeing provided with the said portion at one end thereof and beingdetachably connected to its spindle at its other end. Thus, the saidother end of each arm maybe provided with a threaded spigot which islocated freely in a hole in the respective spindle, the spigot having anut threaded thereon by means of which the arm is bolted to the spindle.

The means for rotating the or each ring may comprise at least one ramwhich acts directly upon the respective ring or is connected thereto byan operating linkage.

The invention also comprises a gas turbine engine provided with a vaneoperating mechanism as set forth above. Thus the said vanes may bevariable stator vanes of a compressor of the engine.

The invention is illustrated, merely by way of example, in theaccompanying diagrammatic drawings, in which:

FIGURE 1 is a view, partly in section, of part of a gas turbine engineprovided with a vane operating mechanism in accordance with the presentinvention,

FIGURE 2 is a broken-away sectional view showing part of the structureof FIGURE 1 on a larger scale,

FIGURE 3 is a broken-away plan view looking in the direction of thearrow 3 of FIGURE 2,

FIGURE 4 is a broken-away sectional. view showing part of the structureof FIGURE 2 on a yet larger scale,

FIGURE 5 is a broken-away sectional view taken on the line 55 of FIGURE4, and

FIGURE 6 is a broken-away sectional view taken on the line 6-6 of FIGURE5.

Referring to the drawings, a gas turbine by-pass engine 10 has an enginecasing 11 within which there are mounted in flow series a low pressurecompressor 12, a high pressure compressor 13, combustion equipment (notshown) and high pressure and low pressure turbines (not shown).

Part of the air compressed by the low pressure compressor 12 passes to aby-pass passage 14, the by-pass passage 14 being disposed between theengine casing 11 and a casing 15 which forms the outer casing of thehigh pressure compressor 13. The casing 15 is mounted concentricallywithin the engine casing 11 and is supported therefrom by way of aplurality of angularly spaced apart struts 16.

The high pressure compressor 13 has angularly spaced apart variablestator vanes which are arranged about the engine axis, the vanes 20being arranged in three axially spaced apart rows. Each of the vanes 20has radially extending spindles 19, 21, rotation of the spindle 21effecting pivotal movement of the respective vane 20.

Each of the sets of vanes 20 has a ring 22 associated with it anddisposed axially upstream of it. Each of the rings 22 is mountedconcentrically about the engine axis and is rotatable about this axisthrough a predetermined angular range.

Although the rings 22 are shown disposed axially upstream of the vanes20, and this is the preferred construction, in some cases the rings 22could well be disposed downstream of the respective row of vanes 20.

The rotation of the rings 22 is eifected by means of at least one ram 23(FIGURE 3) which is arranged to move the outer end of an arm 24 of apivotally mounted bell crank lever 24, 25. The .arm 25 of the bell cranklever 24, 25 is pivotally connected to the most downstream of the rings22, while the arm 24 is connected to the remaining rings 22 by way ofbell crank levers 26, 27 respectively. Thus operation of the ram 23 willmove the arm 24 through a small angle and will therefore move the rings22 through a small angle.

Each of the spindles 21 is connected to its respective ring 22 by meansof a substantially axially extending arm 30. Each of the arms 30 has acentrally located and relatively thin part 31 (best seen in FIGURE 4),which is flexible so as to accommodate the bending to which the arm 30is subjected in operation.

The downstream portion of each of the arms 30 is provided both with aflange 32, which is located against the respective spindle 21, and witha spigot 33 which is located freely in a hole 34 in the respectivespindle 21. The downstream end of the spigot. 33 is threaded and has anut 35 screwed onto it so as to clamp the spindle 21 between the flange32 and the nut 35.

Each of the arms 30 has an enlarged part-spherical portion 36 at itsupstream end, the part-spherical portion 36 being provided with parallelflat sides 37.

Each of the rings 22 is provided with a plurality of angularly spacedapart apertures 40, in each of which is received the part-sphericalportion 36 of the respective arm 30. As will be seen from FlGURE 5, eachof the apertures 40 is part-spherical and has two diametricallyoppositely disposed straight sided enlarged parts 41. The enlarged parts41 have spaced sides 42 between which the partspherical portion 36 maybe passed when the latter is orientated with fiat sides 37 thereofarranged as indicated in dotted lines in FIGURE 5. The part-sphericalportion 36, after having been orientated to introduce it into itsaperture 40, may then be moved within the aperture through 90 to thefull line position shown in FIGURE 5. In this position, which isillustrated in FIGURE 6, the part-spherical portion 36 is locked in theaperture 40.

The vane operating mechanism shown in the drawings may be assembled byattaching all the arms 30 to their respective rings 22 by entering thepart-spherical portions 36 through the enlarged parts 41 of theapertures 40 and then twisting the arms 30 through 90 so as to effectengagement between the spherical surfaces of the partspherical portion36 and aperture 40. The assembly of each ring 22 with its arms 30 canthen be slid into position so that the spigots 33 enter thecorresponding holes 34 in the sprindles 21, and the nuts 35 can then beplaced on the threaded portions of the spigots 33 and can be tightened.

Alternatively, all the arms 30 of each of the rings 22 can be insertedin the respective spindles 21 and the nuts 35 can be loosely applied sothat the arms 30 can be rotated in the holes 34. The respective ring 22can then be oifered up to the upstream ends of the arms 30 with all thearms 30 in the positions indicated in dotted lines in FIGURE 5. Thisenables the part-spherical portions 36 to slide through the enlargedparts 41. All the arms 30 can then be twisted through 90 and the nuts 35tightened to complete the assembly.

As will readily be appreciated, the arrangement shown in the drawings,provides a simple, effective, and compact way of effecting pivotalmovement of the vanes 20.

Although the invention has been described above in connection with thevariable stator vanes 20 of the high pressure compressor 13, it couldalso of course be used in any compressor, fan or turbine where one ormore rows of vanes (or blades) have to be made variable.

I claim:

1. A vane operating mechanism comprising at least one ring, means forrotating said at least one ring about its axis and through apredetermined angular range, a plurality of angularly spaced-apartvanes, associated with each ring and axially spaced therefrom, saidvanes being arranged about the said axis and each having a radiallyextending spindle rotation of which effects pivotal movement of therespective vane, and an arm connecting each spindle to its respectivering, rotation of the latter effecting pivotal movement of the vanesassociated therewith, locking means for connecting and positivelyretaining each arm to its respective ring, said locking means includingproviding each arm with an integral portion and providing the respectivering with apertures for receiving the integral portion of the arm, eachsaid integral portion and aperture being formed so that the integralportion may be relatively orientated to introduce it into the apertureby relative movement of the integral portion and the aperturesubstantially parallel to the axis of the ring and then relatively movedwithin the aperture to engage sides of the aperture and positivelyretain the integral portion in the aperture.

2. Vane operating mechanism as claimed in claim 1 in which each arm hasa flexible part to accommodate the deformation to which it is subjectedin operation.

3. Vane operating mechanism as claimed in claim 2 in which each saidflexible part is a centrally located and relatively thin part of itsarm.

4. Vane operating mechanism as claimed in claim 1, in

P which each said aperture has a spherical part and a nonspherical partand the said integral portion of each arm is part-spherical and ispositively retained in the spherical part of the aperture, each saidportion having been originally introduced into the said non-sphericalpart of the aperture.

5. Vane operating mechanism as claimed in claim 4 in which thenon-spherical part of each aperture comprises two, diametricallyoppositely disposed, straight sided enlarged parts, the said integralportion of each arm having parallel flat sides for reception within thesaid enlarged parts.

6. Vane operating mechanism as claimed in claim 1, each arm beingprovided with the said integral portion at one end thereof and beingdetachably connected to its spindle at its other end.

7. Vane operating mechanism as claimed in claim 6 in which each spindlehas a hole therethrough and the said other end of each arm is providedwith a threaded spigot which is located freely in the hole in therespective spindle, the spigot having a nut threaded thereon by means ofwhich the arm is bolted to the spindle.

8. Vane operating mechanism as claimed in claim 1 in which the means forrotating each ring comprises at least one ram operatively connected tothe at least ring.

9. A gas turbine engine provided with a vane operating mechanism asclaimed in claim 1.

10. A gas turbine engine as claimed in claim 9 in which the said vanesare variable stator vanes of a compressor of the engine.

References Cited UNITED STATES PATENTS 2,933,234 4/1960 Neumann 2301 142,955,744 10/1960 Hemsworth 230-114 2,976,015 3/1961 Gilbert 253782,999,630 9/1961 Warren et al. 253-78 3,303,992 2/1967 Johnson 230-114FOREIGN PATENTS 1,096,708 2/ 1955 France. 1,022,348 1/1958 Germany.

EVERETTE A. POWELL, ]R., Primary Examiner.

